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Energy harvesting in wireless sensor networks
Pačinek, David ; Kučera, Pavel (referee) ; Hynčica, Ondřej (advisor)
This Bachelor's thesis is dedicated to the power of wireless sensors for use of alternative sources of supply, which is solar energy. The thesis performed on description of photovoltaic panels, availible batteries and their charging. The bachleor's thesis also shows the design and implementation of the circuitry for solar battery charger and datalogger consisting of a microcontroller and GSM module.
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Embedded System with Communication Interface NFC and Wi-Fi
Bugár, Loránt ; Valach, Soběslav (referee) ; Horák, Karel (advisor)
This master’s thesis deals with communication system design via the NFC and Wi-Fi interface. The thesis has two basic goals. The first goal is to create a device that is capable of storing of data and its subsequent transfer via the NFC interface. The second aim is to utilize this device for measuring various physical variables. The IoT technology is employed to fulfill the aforementioned goal. IoT technology is capable of visualizing data in real time and make them accessible via the Internet. The result of this work is an universal device, that contains the most popular communication interfaces, such as I2C, SPI and that is capable of processing measurement data from digital, analogue, and wireless sensors.
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Materials and Components for Lithium-Ion Power Sources
Jirák, Tibor ; Kadlec, Jaromír (referee) ; Paidar,, Martin (referee) ; Vondrák, Jiří (advisor)
The dissertation thesis deals with electrode materials and components for lithium-ion power sources. The thesis works with two different kinds of materials, concretely nanostructured Li4Ti5O12 with spinel basis and LiCoO2 with layered structure. The electrochemical properties, structure and element analysis and utilization possibilities in electrochemical industry of new technological electrode material Li4Ti5O12 were investigated. The influences of admixtures and electrolytes on characteristics of electrode materials with aforesaid active masses were also examined. Low cost price, environmental safety and obtained results of electrochemical measurements and structure analysis refer to wide possibilities of usage electrode material Li4Ti5O12 in the field of electrochemistry.
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Wireless security facility
Gargulák, Lukáš ; Morský, Ondřej (referee) ; Zeman, Václav (advisor)
The content of this thesis is the design, construction and programming of wireless security device. This wireless security system consists of two units. Personal unit and sensor unit. This thesis compares two ISM bands 433 MHz and 868 MHz. The thesis presents a selection of parts for construction wireless security device. The work also deals with the structure of transmitted frames on the link layer. Marginally are discussed ways to reduce consuption AtmelAVR microcontrollers and also two ways of charging Li-Ion battery. It also outlined the firmware of both units. Its complete source code is included on the DVD.
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Stability of aprotic electrolytes in lithium-ion batteries
Krištofík, František ; Máca, Josef (referee) ; Sedlaříková, Marie (advisor)
The Master thesis describe basic electrochemical processes in lithium-ion batteries and characteristic organic polar solvents for these articles. It focuses primarily on the aprotic liquid electrolytes for lithium-ion batteries and the subsequent use of gas chromatography to analyze the collected gas sample from the test article. For this experiment is, in this Master thesis, designed and described experimental arrangement in the form of a glass cell, which allows collection from the space above the working electrode. Finally, the work evaluates the effect of electrode potential on the stability of electrolytes in strongly positive potentials.
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Accumulator tester
Pisca, Marek ; Kadlec, Josef (referee) ; Cipín, Radoslav (advisor)
This master´s thesis is dealing with the theory of Li-ion accumulators and theirs charching. In this thesis has been designed accumulator tester for automatic charging and discharging of Li-ion accumulator. This tester is controlled by microprocessor.
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RF power meter
Hlaváč, Štěpán ; Jedlička,, Petr (referee) ; Drexler, Petr (advisor)
This master’s thesis describes various principles of measurement of electromagnetic waves in a free space and on a line. Used sensors and their real parameters are given for every method. The analysis of protections of high-frequency inputs of measuring instruments is done here and the most suitable method and protections of input for realization are chosen. The analysis of design of secondary protection of high-frequency input is done in this project. The protection of input is realized and measured. The suitable method of measurement is chosen as well as the sensor for measurement of power. The block diagram and circuit diagram of the meter of power are designed. According to designed conception the measuring instrument for measurement of power is realized and its single qualities are measured during the realization. In the final part its precision is measured and the evaluation of results is done.
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Controll Electronics for Effective Supplying of Equipment with Li-Ion Accu by Solar Cells
Horký, Luděk ; Dřínovský, Jiří (referee) ; Urbanec, Tomáš (advisor)
This Bachelor`s thesis deals with questions surrounding the collection and harnessing of solar radiation for use as electrical energy. The aim of this project was to build an effective system for charging Li-Ion batteries by means of solar cells. To this end, four different solar panels currently available were chosen for measuring and evaluation. The most suitable of these was chosen and an electronic control system devised for effectively supplying the Li-Ion batteries. It was necessarily to make solution for problems consequent upont this method of charging this type of battery and make practise realizitaion of this electrical scheme by SMT technology.
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Composite electrode materials for lithium-ion batteries based on LiFePO4 prepared using GAC method
Vilhelm, Ondřej ; Neoral, Jiří (referee) ; Čech, Ondřej (advisor)
Presented work investigates the problem of secondary lithium-ion cells and the different available cathode materials. We have prepared samples of LiFePO4 with the addition of different kinds of carbon materials such as Super P, Vulcan and expanded graphite. We have always created the sample with and without surfactant. Developed samples were compared by measuring electrochemical methods (cyclic voltammetry, charge and discharge cycles and impedance spectroscopy). We also modeled the three-point cell for measuring electrochemical electrode materials.
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Accumulator Charger with Microcontroller
Losenický, Roman ; Punčochář, Josef (referee) ; Šebesta, Jiří (advisor)
My master thesis is focused on intorducing, analysing and describing the microprocessor controlled charger. The thesis is firstly describing and analysing the topic of accumulator cell charging for common technologies. Than there is detailed description of specific accumulator cell types (NiMH, NiCd and Li-ion) which is the microprocessor controled charger intend for. The next part of this thesis is showing the proposal of the charger. There is the block diagram, charger detailed schematics based on this block diagram. There is also list of the possible useful componets neccessary for charger assembling. All this is used for the final proposal of the chager itself. The main scope of this thesis is than the charger's microcontroler firmware decribed at the end of this thesis. Finaly confirmation of the charger proper proposal and assembly is the battery charging with the given basic parameters.
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